Safety helmet



FIG. 1 is a top, front and right-side perspective view of a safety helmet showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a right-side elevational view thereof, the left-side elevational view (not provided) being a mirror image thereof;

FIG. 5 is a rear elevational view thereof;

FIG. 6 is a bottom plan view thereof; and,

FIG. 7 is a bottom, front and right-side perspective view thereof.

The broken lines depict parts of the safety helmet that form no part of the claimed design. 

CLAIM The ornamental design for a safety helmet, as shown and described. 